KEEP YOUR HOME SAFE - Designed to withstand 800 lbs. This U 10827 door reinforcement lock with satin nickel finish prevents doors from entering and increases the security of your home and keeps you and your family safe EXTRA HOME SECURITY - Use this high security door reinforcement lock for added security around the home on any swing door of any door thickness. It helps ensure that each door cannot be opened from the outside. CHILD SAFE & TAMPERPROOF This Defender Security door blocker from Prime-Line has a spring loaded design that is both child proof and tamper proof. It can be installed higher on the door where your children cannot reach. In addition, doors can not only be pushed in by intruders, but also protect against lock picking and bumps while in the locked position. Tamper resistant and child-safe design Installs in just minutes using 3" hardened screws Cannot be opened from the outside Requires Drill, 1/8 in. drill bit and phillips screwdriver Chisel may be required if door fits tightly against the jamb (mortised installation)